Astronomer Juan Carlos Munoz reveals the full extent of light pollution over Chile, even while under lockdown, writes Gege Li for an article published in NewScientist.
Light pollution during lockdown
Astronomer Juan Carlos Munoz captured a view of the night sky above Santiago, Chile, from his balcony, using optical techniques. He did this to reveal the extent of light pollution in major cities even while under lockdown.
Technical aspect
To take this image, he covered a lens with a diffraction grating.
How does it work?
Diffraction grating is an optical element that is engraved with grooves that split the light spilling from the buildings and streets into different wavelengths in vertical streaks.
The result reveals
The make-up of the city’s various sources of illumination as a pattern soaring into the night sky.
Sodium lamps have an orange spectra, metal halide lamps predominantly emit green, blue and violet light, while white LEDs are the brightest and emit across the visible spectrum.
Illuminate cities efficiently
Munoz says he takes such pictures to raise awareness of light pollution and hopes people can work together to illuminate cities in a more efficient way.
He says, “The night sky is a natural heritage that all citizens deserve to enjoy regardless of where they live, and therefore it must be protected from pollution, just like oceans or the atmosphere.”
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Source: NewScientist
